Using checkboxGroupInput for interactive Shiny map

Question

I'm trying to filter markers on a map by using the Check Box Group Input.

  titlePanel("Toronto Auto Thefts"),
  leafletOutput ("map", width = "100%", height = "100%"), 

  absolutePanel( 
                checkboxGroupInput("checkGroup", h3("Week Day"), 
                                   choices = list("Monday" = 1,
                                                  "Tuesday" = 2,
                                                  "Wednesday" = 3,
                                                  "Thursday" = 4,
                                                  "Friday" = 5,
                                                  "Saturday" = 6,
                                                  "Sunday" = 7),
                                   selected = 1))
)

The ui part seems ok because the check box is showing up appropriately.

server <- function(input, output, session){
  #filtered <- reactive({data[data$occurrencedayofweek != input$checkGroup]}) 


  output$map <- renderLeaflet({
    leaflet(data = data) %>%
      addTiles() %>%
      addMarkers()
  })

  observe ({
    proxy <- leafletProxy("map", data = data)
    proxy %>% clearMarkers ()
    if (data$occurrencedayofweek %in% input$checkGroup) {
      proxy %>% addMarker()}
    else {
      proxy %>% clearMarkers() %>% clearControls()}
  })
  }

I believe it is the server that is causing problems, however I'm not sure how to fix it.

If your input can contain multiple choices from the user, the filter condition should be something like `subset(data, !(occurrencedayofweek %in% input$checkGroup))`. Otherwise, the server logic might fail in case several choices or no choices are selected — Gregor de Cillia, Dec 25 '19 at 16:52
@GregordeCillia I've changed the filter function, but I'm not getting an error saying that server.R is returning a list. — softsoap, Dec 25 '19 at 17:15

score 1 · Answer 1 · answered Dec 28 '19 at 11:16

This is my approach to the problem. I couldn't tweak your code properly so I rewrote part of it. It's easy to follow I think. In addition I added sample data (always a good practice to add a slice of your dataset).

library(shiny)
library(leaflet)

# c("Monday","Tuesday","Wednesday", "Thursday", "Friday","Saturday","Sunday")

mydata <- data.frame(occurrencedayofweek = c(1:7),
                         longitude = c(10.47, 10.48, 10.49, 10.50,10.51, 10.52, 10.53),
                         latitude = c(45.76, 45.77, 45.78, 45.79, 45.80, 45.81, 45.82))

shinyApp(

ui <- fluidPage(

  leafletOutput ("map"),

  checkboxGroupInput("checkGroup", "Week Day",
                     choices = c("Monday" = 1,
                                    "Tuesday" = 2,
                                    "Wednesday" = 3,
                                    "Thursday" = 4,
                                    "Friday" = 5,
                                    "Saturday" = 6,
                                    "Sunday" = 7),
                     selected = 1)
),

server <- function(input, output, session){

  output$map <- renderLeaflet({
    leaflet() %>%
      addTiles() %>%
      addMarkers(data = mydata,
                 ~longitude,
                 ~latitude,
                 group = "mygroup")
  })

  mydata_filtered <- reactive(mydata[mydata$occurrencedayofweek %in% input$checkGroup, ])

  observeEvent(input$checkGroup, {
    leafletProxy("map", data = mydata_filtered()) %>%
      clearGroup ("mygroup") %>%
      addMarkers(lng =  ~longitude,
                 lat = ~latitude,
                 group = "mygroup")
  })

 }

)

Using checkboxGroupInput for interactive Shiny map

1 Answers1